firstobject XML Editor is a nifty, free XML editor. Best part is, it handles Unicode flawlessly, at least as far as I’ve seen. It even handles UTF-8 both with and without BOMs, which is a fairly common failing I’ve run across in other text and XML editors. Ooze

firstobject.com has a freeware XML Editor they are giving away. You download the zip file and when expanded its a single executable. Apparently these guys write software in C++. No installation mess, just click on the executable and instant XML editor. Mark Orlando
Features

Parse, format, indent, large documents, no Java and no MSXML dependency! Works with incomplete XML documents, logs, and with HTML.